Apparatus for flattening prints



Aug. 9, 1932. R. s. HOPKINS 1,870,626

APPARATUS FOR FLATTENING PRINTS Filed Feb. 15, 1930 5 Sheets-Sheet 1Fig.1.

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Aug. 9, 1932.

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APPARATUS FOR FLATTENING PRINTS Filed Feb. 15; 1930 3 Sheets-Sheet 2 L l2; 7 a M gwvenl oz 1295 8. Ho/nkins.

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atkcrzm 1 0 Patented Aug. 9, 1932 UNETED STATES PATENT OFFNE ROY S.HOPKINS, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COM- PANY, OFROCHESTER, NEW YORK, A CORPORATION OF NEW YORK APPARATUS FOR FLATTENING-PRINTS Application filed February 15, 1930.

This invention relates to photography, and more particularly to a methodand apparatus for flattening prints. One object of my invention is toprovide a method of treating photographic prints, particularly glossyphotographic prints, so that they can be made to lie flat without manualoperations. Another object of my invention is to provide a method offlattening prints which does not in any way injure the prints and whichwill render them permanently flat. Another object of my invention is toprovide a machine through which the prints may be passed to flattenthem. Still another object of my invention is to provide a machine witha. conveyor by which the print is first carried past a steam chamber andthen is passed about a roller which flexes the print while in a steamedcondition. Other objects will appear from the following specification,the novel features being particularly pointed out in the claims at theend thereof.

Considerable difliculty has arisen in the photographic business in thatafter prints are made there is a tendency for the print tocurl, usuallywith the emulsion innermost. This is probably due to the fact that thesupport, whet-her it be paper or a cellulosic support, shrinks andexpands under the effect of moisture to a different extent than does thelight sensitive emulsion coated side. This emulsion coating is usuallyprepared with a gelatine carrier. When the prints have been developed,fixed and washed in the various fluid treatment baths, the paper orother base has a chance to expand and contract a number of times, asdoes also the emulsion coated side.

Since the amount of moisture which the two parts of the print, that is,the base .and the sensitive coating, may receive is different, there isnormally a stretching action in one part which is greater than that ofthe other part. This results in a print which buckles or curls andusually the emulsion coated side expands less and is, therefore, curvedin a concave direction. It is to overcome these difliculties that thepresent invention is particularly directed.

Corning now to the drawings wherein like Serial No. 428,639.

reference characters throughout Figure 1 is a side elevation of amachine constructed in accordance with and embodying a preferred form ofmy invention.

Figure 2 is a similar side elevation but taken from the opposite side ofthe machine with the conveyor in a raised position.

Figure 3 is a fragmentary view, partially in section, through themachine shown in F igure 1.

Figure 4 is a top plan view of the machine shown in Figure 1, withcertain parts being removed for the sake of clearness.

Figure 5 is an enlarged detail View, partially in section, showing asmall portion of a print conveyor and a print flexing roller.

And, Figure '6 is an enlarged fragmentary view of a switch which may beoperated by a portion of the conveyor frame.

This machine preferably consists of a base 1 from Which legs 2 extendupwardly, these legs being connected by a frame 3 which is substantiallyrectangular in shape. To the frame 3 there is hinged upon the shaft 4 asecond frame 5, as is best shown in Figure 3. This frame carries a beltconveyor 6 which passes over a series of rollers 7, 8, 9 and 10.

Rollers 7 and 10 are fixedly mounted with respect to the frame 5although, of course, they are moved when the frame 5 is swung about itspivot.

Rolls 8 and 9 can be moved relative to the frame 5. Referringparticularly to Figure 4 it can be seen that the roll 8 is carried by apair of arms 11 which, by means of the springs 12 are normally turnedabout a shaft 13 in the direction shown by the arrow in Figure 3, theends is of the springs 12 engagdenote like parts ing the pins 15 of thearms 11. This roller merely serves as a tensioning device to alwaysexert an equal pressure upon the conveyor belt 6.

In the center of the shaft 13 there is an adjustable nut 16 which can beused to vary the tension on both of the springs 12. This is merely foran initial setting since after the tension on the springs has once beenadjusted correctly it does not need further 1 adjustment.

The roller 10 is mounted to turn freely upon a shaft 4 which extendsthrough the inside of roller 10, as indicated in Figure 4 in dottedlines. Upon this shaft 4 there are mounted a pair of side arms 16 and17, the latter being provided with an extension 18 which serves as ahandle as best shown in Figure 1.

This handle can move about the shaft 4 and can be held in an adjustedposition by means of a set screw 19 which passes through an arcuate slot20 in the plate 21, this plate being permanently affixed in a suitablemanner to the frame 5.

By altering the position of the handle 18, the position of roller 9 canbe altered in such a way that the belt is drawn more tightly or lesstightly about the roller 10 an the angle to which the belt contacts withthe roller 10 can be varied.

In order to drive the belt, the following mechanism is used: Roller 9carries affixed to the end thereof a gear 22, gear 22 meshing with apinion 23 permanently aflixed to the shaft 4.

The shaft 4 extends through a bearing 24 on the frame 5 and through asecond bearing 25 which forms a part of the upper frame 3. A pulley 26is affixed to the outer end of the shaft 4 and this pulley, as bestindicated in Figure 2, is driven in the following manner:

A belt 27 connects pulley 26 with a small pulley 28 which, in turn, isfastened to move with a large pulley 29. Pulley 29 is connected by meansof a belt 30 with a pulley 31 carried on a motor shaft 32, the motor 33being preferably mounted upon springs 35 to eliminate noise andvibration as far as possible.

The motor may be operated through a duplex wire 35 which leads from aline to the motor through a switch 36.

As best shown in the detail Figure 6, the switch 36 is provided with aspring pressed contact making member 37 of a well known variety in whichwhen the contact member is pressed down a circuit is made and when itsprings up into the position shown in full. lines in Figure 6, thiscontact is broken. Portions of the relatively stationary frame 3 and therelatively movable frame 5 are shown in Figure 6. When the frame 5 ismoved away from its operating position,

that is to say, when the frame 5 is swung uptoward the position shown inFigure 2 the circuit is broken since the bottom of the frame member 5 nolonger contacts with the spring pressed plunger 37. As soon, however, asthe frame 5 is swung down into an operative position, the frame strikesthe plunger 37 and makes the circuit, causing the motor to run andcausing the belt 6 to move through the chain of pulleys and belts abovedescribed.

As best shown in Figures 3 and 5, inorder to hold a print P against theconveyor belt 6, a plurality of wires 38 are stretched between tworelatively fixed rods, 39 and 40. The ends of the wires are turnedaround these rods and attached to screws 41 and 42 in the rods.

The belt 6 moves whereas the wires remain stationary, but as the surfaceof the print contacts with the conveyor belt and only a very smallsurface of the print contacts with the stationary wires, the prints aremoved.

There is a table 43 supported by the main frame 3 of the machine. Thistable furnishes a place from which prints are moved toward the conveyor.A print is directed between the opening 44 just beneath roller 7 andjust above the rod 39.

A print is then caught by the moving belt 6 andmoved to what I call asteam chamber 45 and from this chamber they pass above the rod and aboutthe roller 10. The prints, are flexed by the belt pressing them upon theroller 10 and they face from this roller in a ,flattened'condition.

, The steam chamber is that part of the machine which lies between thelower side of the belt 6 and the upper side of the hot water pan 46.This pan is equipped with a flange 47 which rests on the rails 48carried by the legs 2 of the machine.

In order to steam the prints, water is placed in the pan 46 and thiswater is kept at the proper temperature by means of any standard typeheating unit here shown as an electric heating element 49 which may beconnected witha circuit by means of a duplex wire 50, there preferablybeing a switch 51 as shown in Figure 1 to control the circuit.

I prefer to heat the water until a small amount of steam passes up intothe chamber 45. I have found that it is not necessary to have the waterboiling to any considerable extent as good results can be obtained fromvapor arising from the water without any considerable quantity of steam.

I have found out that by steaming the back of the print, that is, thesupport or paper side of the print and while the print is in a steamedcondition by rolling or flexing the print about some object such as aroller that the prints will flatten out and will remain flat thereafter.Just what the action of the steam on the print is I am not certain, but7 When a paper back of a print is submitted 7 to steam it does notbecome damp but just becomes soft. Ordinarily when an emulsion surfacedprint, particularly a glossy emulsion surfaced print becomes dry, theemulsion is quite brittle and if it is bent about a roller or ruler forflattening it will crack and thus be spoiled.

However, if the paper on the back of the print is steamed first theemulsion surface, although not directly submitted to steam itself,becomes softened to such an extent that it may stretch. When the printis flexed the emulsion surface is stretched to a greater extent than isthe paper base and the emulsion surface seems to retain this stretchedaction so that it will not thereafter cause the print to curl.

I believe that the reason why photographic prints curl when they aredried. in the first instance is that the emulsion has not stretchedsufficiently to compensate for the shrinkage of the paper after that hasstretched by being submitted to the various fluid treatment operations,but whether or not this theory is correct, by the method I have justdescribed which can be conveniently accomplished by means of the machinewhich I have also above described, produces prints which lie permanentlyflat after they have once been treated by the steaming and flexingmethod.

The operation of my machine is as follows. An operator places a stack ofprints to be flattened upon the shelf 43 and directs them, one at atime, into the opening 44.

From this position they will be moved by the moving belt 6 across thesteam chamber 45 and from the steam chamber 45 they are moved about theroller 10 by which they are flexed according to the amount of the belt 6which lies in contact with the roller 4.

As this contact can be changed by moving the handle 18 and adjusting theset screw 19, the degree of flexing can, if necessary, be nicelyadjusted.

I have found, however, that the amount of flexing is not particularlycritical because the print is in a softened condition and seems toreadily take a set in-a flat position after being steamed and flexed.

It should, of course, be understood that the prints which are introducedinto this flattening machine are made in the usual way and dried in theusual way, that is to say, a print may be dried on stretchers or theymay be dried upon ferrotype plates or on the drum drying machines suchas are on the market.

I have found out that where prints are dried on a drum dryer, they areconsiderably easier to flatten than those which are dried by other usualmethods. For instance, I have successfully flattened prints from a drumdryer by merely passing them over the steam bath without flexing themabout a roller 10. While this flattens the prints entirelysatisfactorily, if the prints are dried by some of the other methods itseems preferable to flex the prints at the end of the steam operation tomake sure that the emul sion has stretched a suflicient distance topermit the print to thereafter lie flat.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A print flattening machine including a steam chamber, a conveyor formoving prints over the steam chamber, means for holding prints againstthe conveyor and exposing a face of the prints to the steam.

2. A print flattening machine including a steam chamber, a conveyor formoving prints over the steam chamber, means for holding prints againstthe conveyor and exposing a face of the prints to the steam, said meansexposing one surface of the print to the steam, said conveyor beingadapted to protect the other surface of the print from steam.

3. A print flattening machine including a steam chamber, a conveyor formoving prints over the steam chamber, means for holding prints againstthe conveyor and means including the conveyor for flexing the print.

4. A print flattening machine including a steam chamber, a conveyor formoving prints over the steam chamber, means for holding prints againstthe conveyor and means including the conveyor for flexing the print,said means being so located with respect to the steam chamber thatprints in a steamed condition may be flexed.

5. A print flattening machine including a steam chamber, a conveyor formoving prints over the steam chamber, means for holding prints againstthe conveyor including a plurality of spaced wires through which steammay pass to one face of a print moved by the conveyor.

6. A print flattening machine including a steam chamber, a conveyor formoving a print over the steam chamber, a print flexing roller, saidconveyor passing partially around said roller whereby prints may beflexed While in a steamed condition.

7. A print flattening machine including a steam chamber, and endlessconveyor for moving a print over the steam chamber, a print flexingroller against which said endless conveyor contacts, and means fornormally exerting a substantially fixed pressure upon said endlessconveyor whereby a steamed print may be bent about the print flexingroller.

Signed at Rochester, New York this 12th day of February, 1930.

ROY S. HOPKINS.

